In copending U.S. patent application Ser. No. 613,108, filed May 23, 1984, which is entitled "Module Processing Apparatus and Modules for Use Therewith" and which is owned by the assignee of the present invention and application, there is disclosed a unique load module which employs a flexible load arm. More particularly, the load arm is made from hardened steel having a concave cross-sectional shape. A system of rollers is utilized to bend and guide the load arm as it is extended and retracted during the transportation of a workpiece, such as a silicon wafer, from one location to another. One roller in particular (i.e., a guide roller) functions to maintain the load arm horizontal and level.
Because the longitudinal edges of the load arm, which edges are relatively sharp due to the thinness of the load arm and its metal construction, are in constant contact with the guide roller, the load arm causes chafing of the guide roller, especially if the load arm moves laterally relative to the guide roller during the extension and retraction of the load arm. Such chafing of the guide roller is disadvantageous because it shortens the operating life of the guide roller, thereby necessitating its rather frequent replacement.